This invention is concerned with improvements in the generation of electricity by wind power.
Shortages and increased cost of fossil fuels have stimulated renewed interest in the use of wind power to generate electricity. Electrical generators mechanically coupled to wind-driven rotors have been the subject of intense research and development, but problems of cost, reliability, efficiency, and safety have limited the adoption of such wind generator apparatus.
In an effort to accommodate a wide range of wind velocities, to provide self-starting blades, and to solve overload and overspeed problems, complex and expensive pitch changing mechanisms have been proposed. Fixed-pitch blades, while generally less expensive than variable-pitch blades, have not had the desired efficiency and safety and in some instances have not been self-starting. Manual or motor-driven yawing devices have often been required in order to orient rotors relative to the wind. Expensive cantilever tower support arrangements have been employed that are difficult to erect and that create difficulties in servicing the rotor and head assembly.
In order to obtain maximum benefit from a wind-driven generator, it is desirable that the generator be capable not only of supplying local needs when the wind velocity is sufficient but also of feeding excess power to the AC utility lines. When connected to the AC lines, the generator must generate electricity that is compatible with the AC on the lines and must not constitute a hazard to power company personnel.
In general, the prior art has failed to fill the need for a practical wind-driven generator.